// JavaScript Document
var interval = 5000;
	var random_display = 0;
	var imageDir = "images/slideshow/";
	var imageNum = 0;
	imageArray = new Array();
	imageArray1 = new Array();
	
	imageArray[imageNum++] = new imageItem(imageDir + "60.jpg");
	imageArray[imageNum++] = new imageItem(imageDir + "10j.jpg");
	imageArray[imageNum++] = new imageItem(imageDir + "403.jpg");
	imageArray[imageNum++] = new imageItem(imageDir + "30r.jpg");

	var totalImages = imageArray1.length;

	function imageItem(image_location) {
		this.image_item = new Image();
		this.image_item.src = image_location;
	}
	function get_ImageItemLocation(imageObj) {
		return(imageObj.image_item.src);
	}
	
	function randNum(x, y) {
		var range = y - x + 1;
		return Math.floor(Math.random() * range) + x;
	}

	function getNextImage() {
		if (random_display) {
			imageNum = randNum(0, totalImages-1);
		}
		else {
			imageNum = (imageNum+1) % totalImages;
		}
		var new_image = get_ImageItemLocation(imageArray1[imageNum]);
		return(new_image);
	}

	function getPrevImage() {
		imageNum = (imageNum-1) % totalImages;
		var new_image = get_ImageItemLocation(imageArray[imageNum]);
		return(new_image);
	}

	function prevImage(place) {
		var new_image = getPrevImage();
		http_string = new_image.substr(0,new_image.search("/images"))+1;
		img_display = new_image.substr(http_string.length);
		document.getElementById(place).style.background = "url("+img_display+") center center no-repeat";
		opacity(place, 50, 100, 3000);
	}

	function switchImage(place) {
		var new_image = getNextImage();
		http_string = new_image.substr(0,new_image.search("/images"))+1;
		img_display = new_image.substr(http_string.length);
		document.getElementById(place).style.background = "url("+img_display+") center center no-repeat";
		opacity(place, 50, 100, 3000);
		var recur_call = "switchImage('"+place+"')";
		timerID = setTimeout(recur_call, interval);
        }

function opacity(id, opacStart, opacEnd, millisec) {
    //speed for each frame
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        	}
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}

function imagearr(s) {
	z=0;
	while(s.search('/')!=-1) 
	{
		imageArray1[z] = new imageItem(imageDir + s.substr(0,s.search('/')));
		s = s.substr(s.search('/')+1);
		z++;
	}
	totalImages = imageArray1.length;
}